This invention relates to weighing systems, and more particularly to an apparatus and method for weighing steel coils.
Steel coils, and other similar coils, are weighed at various times during their production and distribution using coil scales or other coil weighing apparatuses. The coil weighing apparatuses may be located in steel mills and other locations where the environment may include heat, dust, vibration, and other factors. Further, coils are heavy, weighing up to 60,000 pounds (27,000 kilograms) or more. In a production environment, a coil weighing apparatus incurs ongoing maintenance costs due to use and environment.
Coil weighing apparatuses use load cells for measuring the weight of a coil. The accuracy and longevity of load cells may be reduced by factors such as uneven loading, impact shocks to the cell, overloading, and other use and environmental considerations. When placing a heavy coil on a coil scale, the coil may be dropped onto the scale, not placed evenly onto the scale, or may be misaligned resulting in the coil rolling or bouncing and possibly causing deformation of the scale and load cells. For this reason, maintenance and replacement of load cells in a weighing apparatus has been necessary.
Maintenance of coil weighing apparatuses may include changing load cells due to damage or for routine replacement. Additionally, when past coil weighing systems were subjected to deformation, shims were placed under portions of the scale to maintain proper alignment and attachment of the load cells. Other periodic or occasional maintenance and repair may be required, such as lubrication of moving parts.
However, past coil weighing systems have been difficult to assemble, repair, and maintain. For maintenance or repair of past coil scales or weighing systems, the entire coil weighing system had to be lifted out and disassembled, thereby increasing maintenance costs. Some past coil weighing systems required as much at twelve hours for disassembly and reassembly. Increased maintenance time resulted in reduced operational time for both the scale and the production operation utilizing the coil scale.
Some past weighing systems included a base and a weighing platform where certain platform members were integrally connected to the base. In the past, such integration weighing systems were thought necessary for achieving the rigidity needed for weighing heavy steel coils. Additionally, integrated structures were thought necessary to maintain alignment of the weighing assembly during operation and to resist the forces created when steel coils were placed upon the weighing apparatus.
The platform integrated with the base of prior weighing apparatuses complicated maintenance tasks and increased maintenance costs. When platform members were integrated with the base, additional time was required to disassemble the weighing apparatus for service or repair. This additional time increased the maintenance costs and also decreased the utilization of the weighing apparatus. Because a weighing apparatus may be an essential component of the steel production process, the additional maintenance time also decreased the productivity of an entire production line.
Further, the weight capacity and measurement accuracy of a coil weighing system depends in part upon the selection of the load cell. Thus, in steel coil production operations producing coils of different sizes and weights, certain load cells had to be changed to accommodate different weight coils. With load cells being difficult to change in past coil weighing systems, adapting to different size coils was difficult and time consuming, if even possible. Past weighing apparatuses had to be disassembled and reassembled, risking damage to the load cells and other components in the weighing system. In the past, it was impractical to use one coil weighing apparatus when different sizes or weights of coils needed to be weighed.
Certain portions of coil weighing apparatuses in the past have also been susceptible to corrosion and deterioration. Steel coils have been produced from pickled, tempered, cold rolled, galvanized, and other types of steel. Additionally, the steel formed into steel coils may have been coated with other types of coatings and chemical treatments. The coatings and other chemicals used during the steel manufacturing process have contacted the components of prior steel coil weighing systems. As a result, care had to be taken to protect past coil weighing apparatuses from corrosion adding to the cost of the weighing system.
Other weighing systems have emphasized the need to protect load cells from damage (see U.S. Pat. No. 5,739,478). Such past systems have required disengaging the load cells prior to placing an article to be weighed on a weighing platform. In this fashion, transitional or shock loads could be dissipated prior to engagement of the load cells. While this design may have protected the load cell from a shock load, these past systems added complexity and cost to the design and maintenance of the weighing system.
There continues to be a need for weighing apparatuses with improved maintenance and operational costs.
The disclosed steel coil weighing apparatus comprises a base having a structure capable of supporting the weighing apparatus and an article to be weighed and having a base portion capable of contact with a load cell, a platform positioned above the base and having a platform portion capable of contact with a load cell, at least one load cell positioned between a base portion and a platform portion capable of providing a signal corresponding to the weight of an article to be weighed, and at least one guide capable of aligning the base and the platform.
Also disclosed is a method of weighing a steel coil comprising assembling a steel coil weighing apparatus, aligning the platform and the base, the alignment being accomplished by the guide, positioning a steel coil on the platform, receiving the signal provided by the load cell, and calculating the weight of the steel coil.